Drill



. y 1, mm, 1499,55

S. T. SKEEN DRILL Filed AUE. l, 1922 I/v VENTOR 5. T Skeen sww wmw ATTORNE rs Mit SAMUEL T. SKEEN, 0F OENTRALIA. ILLINOIS, ASSIGNOIL 0F ONE-HALF T0 QHARLES E.

STEAD, QF GENTEALIA, ILLINOIS.

DRILL.

Application filed August 1, 1922. Serial No. 578,858. i T

To alZ whom it may concern:

Be it known that I, SAMUEL T. SKEEN, a citizen of the/United States of America, and a resident of Centralia, in the county of Marion and State of Illinois, have invented certain new and useful Improvements in Drills, of which the following is a'full, clear, and exact description, reference being had to the accompanyingdrawings, forming a partof this specification.

This invention-relates to improvements in drills and particularly to that class of drills which is used in drilling into coal deposits, and has for one of its objects the production of a simple and inexpensive drill which will form a hole of suficient diameter to permit a ready withdrawal of said drill from said hole after the drilling operation is completed.

Considerable trouble is experienced in connection with the use of the ordinary coal drill because of the difficulty of withdrawing the drill from a deep hole after the drilling operation is completed, and if by reason of l the varying degrees of hardness of the ma terial mined the hole becomes crooked, it becomes necessary at times to have the drill bar shot out by an explosion.

A further object of my invention is to provide a drill which may be operated with much less labor due to the fact that friction caused by the tight fit of the drill stem in the hole is eliminated.

To eliminate the objections set forth above my improved drill is provided with a counter boring blade which is of such size as to form' a hole of greater diameter than the hole formed by the drill blade whereby said drill may be readily removed from said hole even though it be slightly crooked.

A further object of my invention is to provide a drill having cutting elements which may be easily and readily removed for the purpose of sharpening same.

With the foregoing and other objects in view, the invention comprises the novel con struction, combination and arrangement of parts hereinafter more specifically described and illustrated in the accompanying drawings wherein is shown the preferred embodiment of the invention. However, it is to be understood that the invention comprehends changes, variations and modifications which come within the scope of the claims hereunto appended.

Fig. I is a side elevation of a drill constructed in accordance with my invention.

Fig. II is an edgeelevation of the drill shown in Fig. I.

Fig. III is a section on line IIIIII of Fig. I.

Fig. IV is a perspective view of one of the blades forming a part of my improveddrill.

Fig. V is the other blade forming a part of my'drill; a

A designates a drill stem in the form of a spiral conveyor having a flattened end portion 1.

The cutting elements comprise a pair of blades 2 and 3 each provided with an inner portion 4 adapted to engage the flattened end portion 1 of the drill stem and an outer portion 5 shaped to form the cutting portions of said blades. The portion 4 of each of the cutting elements is L-shaped in cross section, the comparatively long leg of said L-shaped portion lying adjacent to a flat face of the portion 1 of the drill stem, and the comparatively short leg of said L-shaped portion lying adjacent to the edge of said portion 1. Formed integral with each of the cutting elements 2 and 3 is an ear 6, said ears being so arranged that each one thereof will overlap the portion 4 of the associated cutting element. (Fig. III). As will be noted by referring to Fig. III, the addition of the ears 6 to the L-shaped portions 4 causes said portions 4 to have the cross sectional shape of a letter J.

Formed integral with the cutting element 2 is a counter boring blade 7, which is extended beyond the cutting element 2 and is provided with a cutting edge 7.

To secure the cutting elements 2 and 3 to the portion 1 of the drill stem, I employ a bolt 8 provided with a suitable nut, said bolt passing through openings in the portions 4 of the cutting elements and an opening in the portion 1.

From the above it is apparent that the cutting elements are very securely held in place on the drill stem even though only one fastening bolt is used as the ears 6 assist the bolt 8 inpreventing independent movement of the cutting elements in any direction.

I claim:

1. A drill comprising a stem, a pair of cutting elements secured to said stem, a portion of each of said cutting elements embracing a port-ion'of the associated cutting element, and means whereby said cutting elements are secured to said stem.

2. A drill comprising a stem, a pair of cutting elements secured to said stem, each of said cutting elements being provided with an extension which embraces the extension of the associated cutting element, and means whereby said cutting elements are secured to said stem.

3. A drill comprising a stem, a pair of cutting elements secured to'said stem, each of said cutting elements being provided with an integral extension which embraces the integral extension of the associated cutting element and means whereby said cutting elements are secured to said stem.

4. A drill comprising a stem, a pair of cutting elements secured to said stem, each of said cutting elements being provided with an integral extension which embraces the integral extension of the associated cutting element, one of said cutting elements being provided with a counter boring blade, and means whereby said cutting elements are secured to said stem.

5. A drill comprising a stem, a pair of cutting elements secured to said stem, each of said cutting elements being provided with a J-shaped extension the J-shaped extensions of the associated cutting elements being adapted to cooperate with each other so that a portion of one of said J-shaped extensions embraces a portion of the associated J- shaped extension, one of said cutting elements being provided with a counter boringlblade, and means comprising a bolt passing through openings in said cutting elements and said stem whereby said cutting elements are secured to said stem.

In testimony that I claim the foregoing I hereunto aflix my signature.

SAMUEL T. SKEEN. 

